<!DOCTYPE html><html lang="en"><head>    <meta charset="UTF-8">    {% block title %}    <title>父模板</title>    {% endblock title %}</head><body><h1>网页头部</h1>{% block body_content %}<h1>网页中间内容</h1>{% endblock body_content %}<h1>网页底部</h1></body></html>